Method for determining an ophthalmic lens

A visual device comprising a lens having a negative power prescription, the lens having a first face and a second face where the second face comprises an initial surface with a central zone of diameter Dini and a peripheral zone of inner diameter Drac greater than the diameter Dini of the central zone, wherein:

• one or more points in the central zone and one or more points in the peripheral zone situated on the inner diameter Drac having an altitude defined with respect to an axis (Z) normal to the second face of the lens and having the centre of the central zone as its origin, the altitude of the peripheral zone being defined as the altitude of a lowest point situated on the inner diameter Drac;
• the peripheral zone has a maximum radius of curvature between the maximum radius of curvature of the first face and the maximum radius of curvature of the central zone;
• wherein the lens is determined based on target values for power and astigmatism for a given direction of glance in the central zone of the second face of the lens and an interpolation formula applied to the central and peripheral zones to define an interpolated surface comprising a connecting zone, the interpolated surface minimizing a merit function for different relative altitudes of the peripheral zone with respect to the central zone.

A visual device comprising a lens having a curvature, the lens having a first face and a second face where the second face comprises an initial surface with a central zone of diameter Dini and a peripheral zone of inner diameter Drac greater than the diameter Dini of the central zone, wherein:

• one or more points in the central zone and one or more points in the peripheral zone situated on the inner diameter Drac having an altitude defined with respect to an axis (Z) normal to the second face of the lens and having the centre of the central zone as its origin, the altitude of the peripheral zone being defined as the altitude of a lowest point situated on the inner diameter Drac;
• the peripheral zone has a maximum radius of curvature between the maximum radius of curvature of the first face and the maximum radius of curvature of the central zone;
• wherein the lens is determined based on target values for power and astigmatism for a given direction of glance in the central zone of the second face of the lens and an interpolation formula applied to the central and peripheral zones to define an interpolated surface comprising a connecting zone, the interpolated surface minimizing a merit function for different relative altitudes of the peripheral zone with respect to the central zone.